Individuals from the Framingham Heart Study's Offspring Cohort (1,039 participants) were followed for up to 11 years to evaluate cardiac index and development of dementia. Thirty-two participants developed dementia over the course of the study, including 26 cases of Alzheimer's disease. Individuals with clinically low cardiac index were two to three times more likely to develop dementia vs. those with normal cardiac index. After factoring for heart disease and other heart conditions, the risk of dementia and Alzheimer's disease actually increased even further.

The authors posit that changes in the heart's ability to pump blood to the brain could affect brain health and function over time. While there is no proven method for prevention dementia and Alzheimer's disease, patients could benefit from taking steps towards reaching a normal cardiac index to reduce this potential risk factor.